1. Field of the Invention
The present invention relates to a data processing apparatus and method for preparing data representative of a plane figure or visible representation, and more particularly to an apparatus capable of automatically preparing supplemental figure data representative of a supplemental figure which is attached to a basic figure or figures to be reproduced on a paper, display screen or other output medium, so that the supplemental figure connects the two basic figures in a continuous and smooth manner, or transform. the basic figure.
2. Discussion of the Prior Art
Generally, a data processing apparatus as described above includes basic figure processing means and supplemental figure processing means. The basic figure processing means is adapted to prepare basic figure data for outputting or reproducing a basic figure on an output medium, and the supplemental figure processlng device is adapted to determine a supplemental figure attached to the basic figure and prepare supplemental figure data necessary to output the supplemental figure on the output medium.
A visible representation to be reproduced on the output medium may consist of a multiplicity of basic figures, each of which has a reference line along which the basic figure extends with a given width. For example, two rectangular basic figures are connected to each other such that a middle point on one of the opposite short sides of one of the two basic figures is aligned with that of the other basic figure. The middle point is an intersection between the relevant short side and the reference line of each rectangular basic figure. The visible representation constituted by the thus connected two basic figures is reproduced on the output medium.
In the above case, there may be formed a V-shaped crevice or gap between the connected short sides of the two rectangular basic figures. Where the two basic figures are connected such that an angle formed by their reference lines is in the neighborhood of 180.degree., the area of the crevice or gap is very small and may disappear when the connected figures are reproduced, or the crevice of the reproduced figures cannot be perceived by the naked eye. Where the angle formed by the reference lines is relatively small, the crevice may be perceived by the naked eye, and the reproduced two basic figures have a poorly connected appearance, or poor continuity at the connection. To eliminate the generation of such a crevice or gap between the connected ends of the two basic figures, it is proposed to provide the data processing apparatus with means for automatically obtaining a supplemental figure which is attached to the basic figures, so as to eliminate the crevice.
As a typical example of the supplemental figure, a sectorial shape as indicated at 98 in FIG. 12 is known. Conventionally, this sectorial supplemental figure 98 is obtained by working out by arithmetic operation an arc whose center is located at an intersection P (reference intersection) between reference lines L1, L2 of two basic figures 100 and 102, and which is contiguous with corresponding long sides 104, 106 of the basic figures.
Also known as the supplemental figure is a quadrilateral as indicated at 110 in FIG. 13. This quadrilateral supplemental figure 110 is conventionally obtained by calculating an intersection Q between extension lines 112, 114 of the corresponding long sides 104, 106 of the two basic figures 100 and 102, and working out by arithmetic operation a figure which is defined by the intersection Q, extension lines 112, 114 and basic figures 100, 102.
Thus, the conventional apparatus requires a comparatively complicated arithmetic operation to work out the appropriate supplemental figure, which results in a considerably long time for preparing figure data representative of a desired visible representation consisting of two or more connected basic figures to which the supplemental figure is attached.
A similar problem is encountered where a basic figure is transformed. For instance, a rectangular basic figure is transformed by rounding one of its longitudinal ends by attaching a semicircular supplemental figure to that longitudinal end.